| 摘要 |
<p>PURPOSE:To improve the brake control property by providing between a valve means and a power piston a key means capable of relative movement in the axial direcion and motion in unison with the valve means after a predetermined stroke and providing a key means with an elastic member. CONSTITUTION:When the follow-up of a control valve 13 is lost with the leftward movement of a rod 10, only an air valve 11 is moved leftward, whereby a valve section 12 and the control valve 13 are separated from each other to introduce air into a chamber 22. As a result, a pressure difference is produced between chambers 21 and 22, causing leftward movement of a power piston 20 to cause leftward movement of a master cylinder operation rod 28. At the instant of end of the servo action an elastic plate 33 of a key 34 engages a large-diameter portion of the air valve 11. At this time, force transmitted through the rod 30 is buffered with the elastic deformation of the elastic plate 33. The reaction force is partly transmitted to the power piston, the rest being transmitted to a pedal through the air valve 11.</p> |
